Curated OER
Diagonals of Quadrilaterals
Teach your mathematicians how to identify different polygons based on their diagonals. Relating quadrilaterals to the different number of diagonals formed, students use the TI to create a visual of their shape.
Virginia Department of Education
Properties of Quadrilaterals
What type of quadrilateral is that? Discover the difference between the types of quadrilaterals. Small groups investigate types of quadrilaterals using geometry software to find their properties. To keep track of the different...
Illustrative Mathematics
Lines of Symmetry for Quadrilaterals
Explore how lines of symmetry help define different categories of quadrilaterals. Looking at a square, rectangle, trapezoid, and parallelogram, young mathematicians discover that each shape has its own, unique symmetry. Encourage your...
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
EngageNY
Properties of Parallelograms
Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...
Mt. San Antonio Collage
Properties of a Parallelogram
More than just a worksheet, the resource provides a thorough guide to navigate through the land of parallelograms. Filled with definitions and theorems, the resource supports learners through problems such as proofs and finding missing...
Inside Mathematics
Quadrilaterals
What figure is formed by connecting the midpoints of the sides of a quadrilateral? The geometry assessment task has class members work through the process of determining the figure inscribed in a quadrilateral. Pupils use geometric...
Curated OER
Properties of Quadrilaterals
In this properties of quadrilaterals worksheet, students use the properties of quadrilaterals to find the perimeter, angle measurement or length of a missing side of a given polygon. Examples and explanations of the properties are...
Curated OER
Area of Quadrilaterals
In this area of quadrilaterals worksheet, 10th graders solve and complete 5 various types of problems. First, they solve each of the triangles shown and find the area of each triangle. Then, students prove that the sum of the squares of...
Curated OER
Quadrilaterals - Diagonals
Young geometers take a look at a variety of shapes and name each one. All of the shapes are quadrilaterals, and they all have intersecting diagonal lines running through them. This presentation would be good to use as an introduction to...
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...
Curated OER
Hands-On: Sums of Angle Measures
In this angle measures instructional activity, students solve six word problems where they are given 6 different polygons, some of which are complex, and must determine angle measures in order to arrive at a solution.
Curated OER
Diagonals of Quadrilaterals
Students find the diagonals of the quadrilaterals. In this geometry lesson, students identify and use properties of quadrilaterals. They define different parts of a quadrilateral shape.
EngageNY
Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
Illustrative Mathematics
Area of a Trapezoid
Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...
Curated OER
Properties of Parallelograms
High schoolers discover properties of parallelograms as they construct a parallelogram using Cabri Jr. They will measure angles and side lengths of their construction and determine the relationship between the diagonals of a...
Curated OER
World of Quadrilaterals
Students define the importance of the properties of quadrilaterals. For this quadrilaterals lesson, students identify the general properties of and compare and contrast the properties of convex and concave quadrilaterals. Students also...
Curated OER
Quadrilaterals
In this quadrilaterals worksheet, 10th graders solve and complete 34 various types of problems. First, they fill-in the family tree with the names of the shapes of quadrilaterals shown. Then, students list the quadrilaterals that have...
Curated OER
Midpoint of a Line Segment
In this line segment instructional activity, 10th graders identify and solve 10 different problems that include determining the midpoint of a line segment in each. First, they determine the midpoint of a segment that connects two points....
Noyce Foundation
Parallelogram
Parallelograms are pairs of triangles all the way around. Pupils measure to determine the area and perimeter of a parallelogram. They then find the area of the tirangles formed by drawing a diagonal of the parallelogram and compare their...
Curated OER
Diagonals to Quadrilaterals II
Learners identify the properties of different polygons. In this geometry lesson, students find the slope of a line and calculate the distance between two lines. They differentiate between similar and congruent polygons.
Curated OER
Developing Formulas for Triangles and Quadrilaterals
In this geometry worksheet, 10th graders determine the area of triangles, parallelograms, trapezoids, kites, and rhombuses. The one page worksheet contains eleven problems. Answers are included.
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Mathematics Vision Project
Module 5: Modeling with Geometry
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...